A water reservoir on the Moon revealed by water diffusion in the Chang’e-5 impact glasses

doi:10.21203/rs.3.rs-1742695/v1

Download PDF

Article

A water reservoir on the Moon revealed by water diffusion in the Chang’e-5 impact glasses

https://doi.org/10.21203/rs.3.rs-1742695/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 27 Mar, 2023

Read the published version in Nature Geoscience →

Version 1

posted

You are reading this latest preprint version

The last decade of lunar exploration has revealed the presence of significant quantities of water on the Moon’s surface, notably characterised by global water retention, release, and replenishment1-9. This led to the proposition that a hydrated layer exists at depth in lunar soils, buffering a water cycle on the Moon globally9. However, so far no candidate reservoir has been identified for this hydrated layer. Here, we report the water abundances, hydrogen isotope compositions, and their core to rim variations, measured in impact glass beads from the Chang’e-5 (CE5) lunar soils. These targets preserve hydration signatures as revealed through water abundance profiles indicating diffusion of solar wind-derived hydrogen inwards into the glasses. Modelling suggests diffusion timescales of less than 661 years at a temperature of 296 K, which could provide an efficient mechanism to explain the recharge of water to sustain the lunar surface water cycle. We estimate that the amount of water contributed by impact glass beads in lunar soils can reach up to 7 × 1013 kilograms. These findings provide the first ground truths that could explain the water cycle at the Moon’s surface and demonstrate potential water reservoirs on airless bodies in the solar system.

It has long been argued that there could be water and other volatile species at the surface of the Moon^10-12. Renewed lunar exploration and advances in remote sensing measurements in the late 1990’s allowed the Neturon Spectrometer on-board the Lunar Prospector mission, to confirm the existence of water ice at the lunar poles¹³. Following this, the Moon Mineralogy Mapper (M³) instrument, on-board the Chandrayaan-1 spacecraft, detected the diagnostic absorption bands of hydroxyl and/or water at 2.8-3.0 μm on the surface of the Moon². More detailed analyses indicated that hydroxyl/water could be present all over the Moon’s surface, which also displayed temporal and spatial variations, with equivalent water abundances ranging between ca. 10 to 1000 mg.g^-1 (Ref. ¹). Further, the Lunar Crater Observation and Sensing Satellite (LCROSS) impact experiment carried out in 2009 provided direct evidence for high water ice abundance (5.6 ± 2.9 wt%) in permanently shadowed regions within Cabeus crater⁴. Elevated water ice abundance in lunar polar regions was further supported by the neutron flux measurements performed by the Lunar Exploration Neutron Detector (LEND) on-board the Lunar Reconnaissance Orbiter (LRO) spacecraft⁵. Lately, the Neutral Mass Spectrometer on the Lunar Atmosphere and Dust Environment Explorer (LADEE) detected exospheric water liberated by meteoroid impacts⁹. Today, there are little doubts that most of the Moon’s surface harbour water. However, the origin(s) of this lunar surface water, and its spatial abundance variations and evolution during regolith gardening remain largely unknown, despite key implications for future lunar surface exploration, and for better understanding the (near)surface water reservoir and processing on Solar System airless bodies.

There are several potential sources and processes that could have contributed to the water inventory at the surface of the Moon, such as (i) solar wind implantation^14-18, (ii) outgassing of volatiles during lunar volcanism^19-21, (iii) deposition of volatile-bearing pyroclastic deposits²² and minerals²³, and (iv) delivery by impacts of comets and asteroids^24-27. It is generally thought that solar wind hydrogen ion implantation could react with fine-grained minerals to produce hydroxyl or water in lunar soils^{3, 7}. The surface water produced and/or delivered on the Moon’s equatorial regions may migrate to polar regions, driven by temperature oscillations^{14, 17, 28, 29}, and could also be partially released to space⁹. Hence, a scenario of lunar water cycle was further proposed to describe the retention, release, and replenishment of water on the surface of the Moon⁹. In order to sustain a water cycle at the surface of the Moon, there should be a hydrated layer (reservoir) at depth in lunar soils⁹. However, finding this water reservoir has remained elusive, despite several studies having investigated the water inventory, and its hydrogen isotope composition, of fine mineral grains in lunar soils^30-32, impact-produced agglutinates²⁵, magmatic and/or volcanic rock fragments (e.g., ref.²⁴), and volcanic glass beads^{19, 33}. Consequently, there must be a yet unidentified water reservoir in lunar soils that has the capacity to buffer a lunar surface water cycle.

The lunar soils returned by the Apollo, Luna, and Chang’e-5 (CE5) missions mainly comprise rock and mineral fragments, pyroclastic glass beads, impact-produced agglutinates, and impact glass beads^{34, 35}. Among these components, the water inventory of impact-glass beads has not yet been investigated in detail, despite these glassy beads being potential candidates for playing a significant role in a lunar surface water cycle. To remedy this issue, we carried out a systematic characterisation of the petrography, major element composition, Raman characteristics, water abundance, and hydrogen isotope composition on the impact glass beads returned by the CE5 mission, aiming to identify and characterise the missing water reservoir on the Moon’s surface.

Water abundance and hydrogen isotope composition of CE5 impact glasses

The studied impact glass beads were hand-picked from a lunar soil sample (sample CE5C0100YJFM00103; ~1 g) scooped by the CE5 lander robotic arm. A total of 117 individual spherical glass beads were characterised using field-emission secondary electron microscopy (FE-SEM), electron probe micro-analyser (EPMA), and Raman spectroscopy (Fig. 1, Supplementary Figs. S1 and S2, Table S1, Extended Data Fig. 1). Among them, 32 impact glass beads characterised by smooth exposed surfaces and chemical compositions consistent with those of bulk CE5 basalts were chosen for in situ water abundance and H isotope analysis using a NanoSIMS (Fig. 1, Extended Data Fig. 1, Supplementary Table S1). The CE5 impact glass beads contain 0-1,909 μg.g^-1 equivalent H₂O, with H isotope compositions ranging from -998 ± 6‰ to 522 ± 440 ‰, and which are negatively correlated with the water abundances (Fig. 2). We also analysed water abundances and H isotope compositions along 6 transects in 5 glass beads (CE5#33,003, 036, 046, 052, and 076, Fig. 1), which show elevated water abundances at the rims that gradually decrease towards the cores, while dD values decrease from cores to rims (Fig. 3, Extended Data Figs. 4 and 5). Three glass beads display sharp decrease in water content from the rims towards the cores, while the other two glass beads display a smoother water abundance variation (Fig. 3, Extended Data Figs. 4 and 5).

Origin of water in CE5 impact glasses

The CE5 impact glass beads are generally characterised by higher water abundances (up to ~ 2,000 μg.g^-1) and lower dD values (~-990 ‰) compared with pyroclastic glasses, impact-produced agglutinates, and melt inclusions reported in previous studies (Fig. 2, Supplementary Table S4). The extremely low dD values measured at the rims of CE5 impact glasses are consistent with the H isotope composition of solar wind^{30, 36}. These low dD values are distinct from other potential lunar water reservoirs, such as indigenous water outgassed during lunar volcanism (dD ~ -300 ‰ to 1,200 ‰)^{20, 33, 37}, water-rich carbonaceous chondrites (dD ~ -200 ‰ to 800 ‰)^{38, 39}, and comets (dD ~ 0-2,500 ‰)^{40, 41}, indicating that the water retained in CE5 impact glasses is of a solar wind origin.

There are two potential mechanisms, degassing and two-endmember mixing, that could explain the negative correlation between water abundances and dD values defined by CE5 impact glasses (Fig. 2). Because the starting solar wind D/H ratio is so low (D/H ~ 3.1×10^-6), the H₂ degassing modelling indicate that D/H fractionation due to H₂ loss would only yield an increase in dD values from about -980 ‰ up to -926 ‰ for 99.9% loss, starting with an initial water abundance in CE5 impact glasses of 2,000 μg.g^-1 (Fig. 2, see Methods). Therefore, H₂ loss from CE5 impact glasses is not a viable mechanism to account for the large dD variations from ca. -998 ‰ to +522 ‰ (Fig. 2). More importantly, the high water content at the rim but low water content in the core of the glass beads is not consistent with the degassing scenario.

In the other scenario, the CE5 impact glasses could have lost most of their water during their high temperature formation, following which solar wind-derived water started diffusing into these glasses. This binary mixing model, between a water-poor but relatively high D/H end-member and a water-rich but extremely low D/H end-member, reproduces well the range of water abundances and dD values measured in CE5 impact glasses (Fig. 2). Modelling requires that the initial water abundances of CE5 impact glass beads are less than 50 μg.g^-1 prior to the addition of solar wind-derived water (Fig. 2). This requirement is consistent with the water abundances measured at the cores of CE5 impact glasses, which are comparable to the instrument H₂O background (ca. 10-30 ppm, see Methods), indicating that any water potentially present in the precursor materials was nearly all lost during formation of the CE5 impact glass beads, prior to the addition of solar wind-derived water. Most importantly, the hydration profiles in CE5 impact glass beads show that solar wind-derived water has diffused inwards into the glasses (Fig. 3), unambiguously demonstrating that the addition of solar wind-derived water post-dated the formation of the impact glass beads.

Impact glasses as the driver for the lunar surface water cycle

The negative correlation between water abundances and dD values and the hydration profiles observed for CE5 impact glass beads reveal that solar wind-derived water can diffuse into and be stored in lunar impact glasses on the Moon’s surface, likely via post-implantation diffusion^{17, 42}. In order to model the diffusion timescale, we used Raman spectroscopy to confirm that water hosted in CE5 impact glass beads is in the form of hydroxyl/molecular water (Extended Data Fig. 6). The diffusion coefficient of hydroxyl/water in glasses⁴³ was referred to modeling the duration timescale of forming the observed hydration profiles of CE5 impact glass beads (see Methods). Diffusion modelling results indicate that the diffusion time needed to produce the observed hydration profiles varies from 26 years to 661 years at a temperature (T) of 296 K, and from 5 to 120 years at T = 313 K (Fig. 3, Extended Figs. 4 and 5, Methods). This short diffusion time indicates that the solar wind-derived water can be rapidly accumulated and stored in lunar impact glass beads. It is interesting to note that one profile on bead CE5#33,036 displays notable post-diffusion water loss at the very rim (Fig. 3, see Method), suggesting that CE5 impact glass beads have the capacity of both incorporating solar wind-derived water and releasing it to the lunar exosphere if T increases. Therefore, we propose that impact glass beads in lunar soils are a prime water reservoir candidate able to drive the lunar surface water cycle (Fig. 4).

Linking a lunar surface water cycle with impact glass beads imply three major processes: (1) formation of impact glass beads, (2) solar wind-derived water implantation and diffusion into the beads, and (3) water release to the lunar exosphere during T increase, possibly due to sunlight irradiation and/or meteoroid impats (Fig. 4). Impact glass beads are produced during melting of lunar soil and regolith targets when impactors hit the Moon. Most of the water present in the precursor materials would have likely been lost during high temperature melting that led to the formation of the impact glass beads. Solar wind hydrogen ions would then be continually implanted into lunar soils and impact glass beads, and would combine with oxygen atoms to form the hydroxyl/water which diffused into the glass interiors under a low temperature and is stored in the phase. This water stored in impact glass beads could then be released to the lunar exosphere due to sunlight irradiation¹⁷ and/or meteoroid impacts⁹.

Some of the CE5 impact glass rims contain higher water abundance (up to ca. 2000 μg.g^-1) than that reported in Apollo agglutinates (<600 μg.g^-1) (Fig. 2); however, they are still not water-saturated compared with terrestrial basaltic glasses of similar chemical compositions that can contain up to 2.43 wt% H₂O⁴⁴. This could be the result of dynamic diffusion and release of water in the impact glass beads controlled by the time-of-the-day temperature oscillations⁸. The dynamic ingress and egress of water in impact glass beads could have acted as a buffer to explain the global and daily variations of water abundance on the lunar surface and in the lunar exosphere^{3, 7, 8}.

Contribution of impact glasses to the lunar surface water cycle

Using the water abundance measured in CE5 impact glass beads and mare basalts⁴⁵, we can estimate the relative contribution of solar wind implanted in space weathered mineral rims, impact glasses, and basalts to the global water inventory along a depth profile in the CE5 regolith (Extended Data Fig. 7). The modal abundance of impact glass beads in lunar soils is referred to 3-5 vol.% estimated from Apollo lunar soils⁴⁶. The impact glass beads are the dominant water reservoir in lunar soils, except in the top <100 nm of the soil where solar wind H⁺ implanted in space weathered rim dominate (Extended Data Fig. 7). Importantly, the major water-bearing phase in CE5 basalts is apatite in which water occurs as hydroxyl occupying the X-site in apatite crystal structure^{47, 48}. The daily temperature variation of 93 K to 423 K on the Moon surface is not high enough to drive hydroxyl out from the apatite structure^{28, 49}, indicating that impact glass beads are likely the dominant target to account for the lunar surface water cycle, except for the outermost space weathered rims (<100 nm).

The global lunar surface is covered by lunar soils with a thickness ranging from about 3 m to 12 m^{50, 51}. Regardless of the contributions of space weathered rims and lunar indigenous rocks, the amount of water in lunar soils contributed by impact glass beads varies from 1.0×10¹² kg to 7.0×10¹³ kg, assuming an average water abundance in impact glass beads of 400 μg.g^-1 (mean value of this study) and a modal abundance of ~3-5 vol.%⁴⁶ (Fig. 4). This estimate is 5 to 6 orders of magnitude higher than the amount of water (2.8×10⁷ kg) contributed from space weathered rims, assuming a layer of 100 nm⁵² and an average water abundance of 1 wt.%³⁰ (Fig.4). Importantly, this estimate provides a minimum quantity of water available at the lunar subsurface, as it does not take into account the water contribution from permanently shadowed regions^{1, 2, 4, 13} and indigenous lunar rocks (e.g., ref. ²⁴). These findings indicate that the lunar soils contain a much higher amount of solar wind-derived water than previously thought, largely stored in impact glasses, which could be a water reservoir for in-situ utilisation in future lunar exploration. This water reservoir is quite easy to extract in terms of the post-diffusion degassing profile of the CE5 impact glass beads (Fig. 3 and Methods).

Implications for water on airless bodies

Asteroid and comet impacts are the major exogenous processes that reshape the surface morphologies of airless bodies, as evidenced by the widespread presence of impact craters on the Moon⁵³, Mercury⁵⁴, and asteroids^{55, 56}. These impacts likely create impact glasses and glass beads on any airless bodies, as evidenced by the studies of lunar soils⁵⁷ and howardites⁵⁸. This study demonstrates that impact glass beads have the capacity to store significant quantities of solar wind-derived water at the surface of airless bodies, in addition to the possible presence of water ice trapped in permanently shadowed areas in polar regions. The presence of water, stored in impact glass beads, is consistent with the remote detection of water at lower latitude regions of the Moon^1-8, 4 Vesta⁵⁹, and Mercury^{60, 61}. Our findings indicate that the impact glasses on the surface of airless bodies in the solar system are capable to store the solar wind-derived water and release them to space.

1. Clark, R.N. Detection of adsorbed water and hydroxyl on the Moon. 326,562-4 (2009).

2. Pieters, C.M., et al. Character and spatial distribution of OH/H2O on the surface of the Moon seen by M3 on Chandrayaan-1. 326,568-72 (2009).

3. Sunshine, J.M., et al. Temporal and spatial variability of lunar hydration as observed by the Deep Impact spacecraft. 326,565-8 (2009).

4. Colaprete, A., et al. Detection of water in the LCROSS ejecta plume. 330,463-8 (2010).

5. Mitrofanov, I.G., et al. Hydrogen mapping of the lunar south pole using the LRO neutron detector experiment LEND. 330,483-6 (2010).

6. Bandfield, J.L., Poston, M.J., Klima, R.L., Edwards, C.S. Widespread distribution of OH/H2O on the lunar surface inferred from spectral data. 11,173-177 (2018).

7. Li, S., Milliken, R.E. Water on the surface of the Moon as seen by the Moon Mineralogy Mapper: Distribution, abundance, and origins. 3,e1701471 (2017).

8. Wohler, C., Grumpe, A., Berezhnoy, A.A., Shevchenko, V.V. Time-of-day-dependent global distribution of lunar surficial water/hydroxyl. 3,e1701286 (2017).

9. Benna, M., Hurley, D.M., Stubbs, T.J., Mahaffy, P.R. & Elphic, R.C. Lunar soil hydration constrained by exospheric water liberated by meteoroid impacts. 12,333-338 (2019).

10. Watson, K., Murray, B., Brown, H. On the possible presence of ice on the Moon. 66,1598-1600 (1961).

11. Watson, K., Murray, B.C., Brown, H. The behavior of volatiles on the lunar surface. 66,3033-3045 (1961).

12. Zeller, E.J., Ronca, L.B., Levy, P.W. Proton-induced hydroxyl formation on the lunar surface. 71,4855-4860 (1966).

13. Feldman, W.C., Maurice, S., Binder, A.B., Barraclough, B.L., Elphic, R.C. & Lawrence, D.J. Fluxes of fast and epithermal neutrons from Lunar Prospector: evidence for water ice at the lunar poles. 281,1496-500 (1998).

14. Schaible, M.J., Baragiola, R.A. Hydrogen implantation in silicates: The role of solar wind in SiOH bond formation on the surfaces of airless bodies in space. J Geophys Res-Planet 119,2017-2028 (2014).

15. Schörghofer, N. Migration calculations for water in the exosphere of the Moon: Dusk-dawn asymmetry, heterogeneous trapping, and D/H fractionation. Geophys Res Lett 41,4888-4893 (2014).

16. Farrell, W.M., Hurley, D.M., Zimmerman, M.I. Solar wind implantation into lunar regolith: Hydrogen retention in a surface with defects. Icarus 255,116-126 (2015).

17. Jones, B.M., Aleksandrov, A., Hibbitts, K., Dyar, M.D. & Orlando, T.M. Solar Wind-Induced Water Cycle on the Moon. Geophys Res Lett 45,10959-10967 (2018).

18. Tucker, O.J., Farrell, W.M., Killen, R.M., Hurley, D.M. Solar Wind Implantation Into the Lunar Regolith: Monte Carlo Simulations of H Retention in a Surface With Defects and the H-2 Exosphere. J Geophys Res-Planet 124,278-293 (2019).

19. Saal, A.E., Hauri, E.H., Cascio, M.L., Van Orman, J.A., Rutherford, M.C. & Cooper, R.F. Volatile content of lunar volcanic glasses and the presence of water in the Moon's interior. 454,192-5 (2008).

20. Tartèse, R., Anand, M., Barnes, J.J., Starkey, N.A., Franchi, I.A. & Sano, Y. The abundance, distribution, and isotopic composition of Hydrogen in the Moon as revealed by basaltic lunar samples: Implications for the volatile inventory of the Moon. Geochim Cosmochim Ac 122,58-74 (2013).

21. Hui, H.J., et al. Cooling rates of lunar orange glass beads. Earth Planet Sc Lett 503,88-94 (2018).

22. Milliken, R.E., Li, S. Remote detection of widespread indigenous water in lunar pyroclastic deposits. Nat Geosci 10,561-+ (2017).

23. Hui, H.J., Peslier, A.H., Zhang, Y.X., Neal, C.R. Water in lunar anorthosites and evidence for a wet early Moon. Nat Geosci 6,177-180 (2013).

24. Greenwood, J.P., Itoh, S., Sakamoto, N., Warren, P., Taylor, L. & Yurimoto, H. Hydrogen isotope ratios in lunar rocks indicate delivery of cometary water to the Moon. Nat Geosci 4,79-82 (2011).

25. Liu, Y., Guan, Y.B., Zhang, Y.X., Rossman, G.R., Eiler, J.M. & Taylor, L.A. Direct measurement of hydroxyl in the lunar regolith and the origin of lunar surface water. Nat Geosci 5,779-782 (2012).

26. Füri, E., Deloule, E., Gurenko, A., Marty, B. New evidence for chondritic lunar water from combined D/H and noble gas analyses of single Apollo 17 volcanic glasses. Icarus 229,109-120 (2014).

27. Joy, K.H., et al. The isotopic composition of volatiles in the unique Bench Crater carbonaceous chondrite impactor found in the Apollo 12 regolith. Earth Planet Sc Lett 540,116265 (2020).

28. Li, S., Milliken, R.E. An empirical thermal correction model for Moon Mineralogy Mapper data constrained by laboratory spectra and Diviner temperatures. J Geophys Res-Planet 121,2081-2107 (2016).

29. Jones, B.M., Aleksandrov, A., Hibbitts, C.A., Orlando, T.M. Thermal evolution of water and hydrogen from Apollo lunar regolith grains. Earth Planet Sc Lett 571,117107 (2021).

30. Hashizume, K., Chaussidon, M., Marty, B., Robert, F. Solar wind record on the moon: deciphering presolar from planetary nitrogen. Science 290,1142-5 (2000).

31. Leich, D.A., Tombrello, T.A., Burnett, D.S. The depth distribution of hydrogen in lunar materials. 19,305-314 (1973).

32. Stephant, A., Robert, F. The negligible chondritic contribution in the lunar soils water. Proceedings of the National Academy of Sciences of the United States of America 111,15007-12 (2014).

33. Saal, A.E., Hauri, E.H., Van Orman, J.A., Rutherford, M.J. Hydrogen isotopes in lunar volcanic glasses and melt inclusions reveal a carbonaceous chondrite heritage. Science 340,1317-20 (2013).

34. Morris, R.V., Handbook of lunar soils. 1983: Lyndon B. Johnson Space Center.

35. Li, C., et al. Characteristics of the lunar samples returned by the Chang'E-5 mission. 9,nwab188 (2022).

36. Epstein, S., Taylor, H.P., Jr. The isotopic composition and concentration of water, hydrogen, and carbon in some Apollo 15 and 16 soils and in the Apollo 17 orange soil. 4,1559-1575 (1973).

37. Tartèse, R., Anand, M., McCubbin, F.M., Elardo, S.M., Shearer, C.K. & Franchi, I.A. Apatites in lunar KREEP basalts: The missing link to understanding the H isotope systematics of the Moon. 42,363-366 (2014).

38. Robert, F., Gautier, D., Dubrulle, B. The solar system D/H ratio: Observations and theories. Space Sci Rev 92,201-224 (2000).

39. Alexander, C.M., Bowden, R., Fogel, M.L., Howard, K.T., Herd, C.D. & Nittler, L.R. The provenances of asteroids, and their contributions to the volatile inventories of the terrestrial planets. Science 337,721-3 (2012).

40. Altwegg, K., et al. Cometary science. 67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio. 347,1261952 (2015).

41. Hartogh, P., et al. Ocean-like water in the Jupiter-family comet 103P/Hartley 2. 478,218-20 (2011).

42. Jones, B.M., Aleksandrov, A., Dyar, M.D., Hibbitts, C.A. & Orlando, T.M. Investigation of Water Interactions With Apollo Lunar Regolith Grains. J Geophys Res-Planet 125,e06147 (2020).

43. Zouine, A., Dersch, O., Walter, G., Rauch, F. Diffusivity and solubility of water in silica glass in the temperature range 23-200 degrees C. Phys Chem Glasses-B 48,85-91 (2007).

44. Hauri, E., Wang, J., Dixon, J.E., King, P.L., Mandeville, C. & Newman, S. SIMS analysis of volatiles in silicate glasses. Chem Geol 183,99-114 (2002).

45. Hu, S., et al. A dry lunar mantle reservoir for young mare basalts of Chang'e-5. Nature 600,49-53 (2021).

46. McKay, D.S., et al. The lunar regolith. 567,285-356 (1991).

47. Boyce, J.W., Tomlinson, S.M., McCubbin, F.M., Greenwood, J.P. & Treiman, A.H. The lunar apatite paradox. Science 344,400-2 (2014).

48. McCubbin, et al. Experimental investigation of F, Cl, and OH partitioning between apatite and Fe-rich basaltic melt at 1.0–1.2 GPa and 950–1000 °C. 4779,83-89 (2015).

49. Ingrin, J., Blanchard, M. Diffusion of hydrogen in minerals. Rev Mineral Geochem 62,291-320 (2006).

50. Zhang, J., et al. Volcanic history of the Imbrium basin: A close-up view from the lunar rover Yutu. Proceedings of the National Academy of Sciences of the United States of America 112,5342-7 (2015).

51. Zhang, J., et al. Lunar regolith and substructure at Chang’E-4 landing site in South Pole–Aitken basin. 5,25-30 (2020).

52. Keller, L.P., McKay, D.S. The nature and origin of rims on lunar soil grains. Geochim Cosmochim Ac 61,2331-2341 (1997).

53. Head, J.W., 3rd, et al. Global distribution of large lunar craters: implications for resurfacing and impactor populations. 329,1504-7 (2010).

54. Strom, R.G., Chapman, C.R., Merline, W.J., Solomon, S.C. & Head, J.W., 3rd Mercury cratering record viewed from MESSENGER's first flyby. 321,79-81 (2008).

55. Jaumann, R., et al. Vesta's shape and morphology. 336,687-90 (2012).

56. Abe, S., et al. Mass and local topography measurements of Itokawa by Hayabusa. 312,1344-1347 (2006).

57. Taylor, G.J., Martel, L.M.V., Lucey, P.G., Gillis-Davis, J.J., Blake, D.F. & Sarrazin, P. Modal analyses of lunar soils by quantitative X-ray diffraction analysis. Geochim Cosmochim Ac 266,17-28 (2019).

58. Singerling, S.A., McSween Jr., H.Y., Taylor, L.A. Glasses in howardites: Impact melts or pyroclasts? 48,715-729 (2013).

59. Prettyman, T.H., et al. Elemental mapping by Dawn reveals exogenic H in Vesta's regolith. 338,242-6 (2012).

60. Harmon, J.K., Slade, M.A. Radar mapping of mercury: full-disk images and polar anomalies. 258,640-3 (1992).

61. Lawrence, D.J., et al. Evidence for water ice near Mercury's north pole from MESSENGER Neutron Spectrometer measurements. 339,292-6 (2013).

There is NO Competing Interest.

He2022NGExtendedData.docx
Article File
He2022NGSOM0610.docx
Supplementary materials
TableS1Mountinformation.xlsx
Table S1
TableS2EPMA.xlsx
Table S2
TableS3Standards.xlsx
Table S3
TableS4CREcorrected.xlsx
Table S4
TableS5literature.xlsx
Table S5

Download PDF

Journal Publication

published 27 Mar, 2023

Read the published version in Nature Geoscience →

Version 1

posted

You are reading this latest preprint version

A water reservoir on the Moon revealed by water diffusion in the Chang’e-5 impact glasses

Status:

Journal Publication

Version 1

Abstract

Figures

Full Text

References

Additional Declarations

Supplementary Files

Status:

Journal Publication

Version 1